High Speed Preparative HPLC Separation of Regioisomers of a Pharmaceutical Intermediate Using Gradients of Methanol in Ethoxynonafluorobutane

Abstract

Highly efficient preparative HPLC separation of a mixture of regioisomers of a pharmaceutical intermediate using gradients of methanol in hexane‐like ethoxynonafluorobutane on a cyano column is described. Such gradients were unique for the mixture to produce significant amounts of individual isomers in a short period of time. The quality of the separation was not affected by a two‐fold increase in the flow rate used. The influence of the injection solvent, sample load, and injection volume on the separation performance was studied. Viscosity of the injection solvent and its volume appeared to play a major role in the successful outcome of the regioisomers' separation, and the polarity of the injection solvent did not seem to affect the separation.

Keywords:

• High speed
• Preparative HPLC
• Gradient
• Methanol
• Ethoxynonafluorobutane
• Regioisomers
• Cyano
• Column